Background: In individuals with coronavirus disease 2019 (COVID-19) pneumonia, radiographic pneumonic infiltrates may persist for several weeks, even after viral clearance, thereby making it difficult to decide on an appropriate treatment and infection control strategy.
Case presentation: We describe a 46-year-old woman with COVID-19 pneumonia who had persistent radiographic pneumonic infiltration and respiratory symptoms for almost 4 weeks after illness onset, despite viral clearance, and was subsequently diagnosed with secondary organizing pneumonia using video-assisted thoracoscopic lung biopsy. Intravenous methylprednisolone was administered at an initial dose of 50 mg/day (1 mg/kg) for 7 days and was tapered to a dose of prednisolone 30 mg/day following improvement in the patient’s respiratory symptoms and chest radiographic findings. The patient was discharged from the hospital 14 days after initiation of corticosteroid treatment. The dose of prednisolone was tapered to 20 mg/day after a month at the outpatient clinic, with further reduction of pneumonic infiltrations seen in a follow-up CT scan on Day 46 of the illness.
Conclusions: To the best of our knowledge, this is the first case report of a pathologically confirmed secondary organizing pneumonia occurring during the convalescent period of COVID-19 pneumonia. Secondary organizing pneumonia should be considered in the differential diagnosis of patients with COVID-19 pneumonia with persistent respiratory symptoms and radiographic pneumonic infiltrations during the recovery phase. In such situations, treatment with steroids may be required, and prolonged isolation of patients with airborne precautions may be unnecessary.